Synthesis, Magnetic and Spectral Properties of Some Metal(II) Complexes of Mercaptoacetic and 3-Mercaptopropionic Acid Derivatives of Vitamin B<sub>1</sub>
作者:Gabriel A. Kolawole
DOI:10.1080/00945719608005126
日期:1996.9
(4'-Amino-2'-methyl-5'-pyrimidinylmethylthio) acetic acid, Hammpta, and the propionic acid analogue, Hammptp, and their copper(II), cobalt(II), zinc(II), palladium(II) and platinum(II) complexes have been synthesized. The pKa values of the acids (at 25 degrees C) are 2.76 (Hammpta) and 2.74 (Hammptp). The complexes were characterized by microanalyses, IR and electronic spectra, conductivity and magnetic susceptibility measurements. While the zinc(II), palladium(II) and platinum(II) complexes exhibit tetrahedral and square-planar geometries, the copper(II) and cobalt(II) complexes exhibit a variety of geometries. One of the copper(II) complexes, [Cu(ammptp)ClH2O], and one of the cobalt(II) complexes, [Co(ammptp)Cl](2), are magnetically concentrated. [Co(Hammpta)(2)Cl-2] is presumed to be low-spin octahedral or square-planar (mu(e) = 2.18 B.M.), whereas the cobalt(II) complexes of Hammptp/ammptp(-) are more prone to being tetrahedral.
(4'-氨基-2'-甲基-5'-嘧啶基甲基硫基)乙酸、Hammpta,以及丙酸类似物Hammptp,及其铜(II)、钴(II)、锌(II)、钯(II)和铂(II)的配合物已被合成。这些酸的pKa值(25℃)为2.76(Hammpta)和2.74(Hammptp)。这些配合物通过微分析、红外光谱、电子光谱、电导率和磁性测量进行了表征。虽然锌(II)、钯(II)和铂(II)的配合物显示出四面体和平面四边形几何结构,但铜(II)和钴(II)的配合物则表现出多种几何结构。其中一种铜(II)配合物,[Cu(ammptp)ClH2O],以及一种钴(II)配合物,[Co(ammptp)Cl]₂,则具有磁浓度。假设[Co(Hammpta)₂Cl₂]为低自旋八面体或平面四边形(μ_e = 2.18 B.M.),而Hammptp/ammptp⁻的钴(II)配合物更倾向于四面体结构。